Comparison of various chromatographic methods for the determination of adsorption isotherms in solutions

Eltekov, Yu. A.; Kazakevitch, Yu. V.

doi:10.1016/s0021-9673(01)94134-2

Cited by 19 publications

(10 citation statements)

References 16 publications

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“…The measurement of equilibrium isotherms is one of the most popular methods to characterize the thermodynamic parameters of the molecular interactions between solvent molecules and the stationary phase. The isotherm should give useful information about the retention of organic compounds and the properties of the stationary phase in the chromatographic columns 1, 2. There are various static and dynamic chromatographic methods for isotherm measurement of the organic modifiers 1–4.…”

Section: Introductionmentioning

confidence: 99%

Examination of the surface heterogeneity of reversed‐phase packing materials with solvent adsorption

Vajda

Bocian

Buszewski

et al. 2010

J of Separation Science

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The adsorption isotherms of acetonitrile, ethanol, 2-propanol, and THF were measured using frontal analysis on six columns packed with octadecyl RP stationary phase. The effect of the bonding density of the end-capped octadecyl bonded phase on the adsorption properties was measured. Adsorption isotherm data were collected from aqueous solutions of the four organic modifiers. The isotherm model for solvent adsorption was selected using two independent parameter estimation methods, the regression analysis and adsorption energy distribution. The fitted isotherm parameters were tested by modeling of overloaded elution bands with the aid of the equilibrium-dispersive model of chromatography. The surface heterogeneity estimations and the effect of the silanol groups on the adsorption of solvents were based on those data.

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Section: Introductionmentioning

confidence: 99%

Examination of the surface heterogeneity of reversed‐phase packing materials with solvent adsorption

Vajda

Bocian

Buszewski

et al. 2010

J of Separation Science

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“…Using water as mobile phase, the adsorption isotherm of methanol presented a lower adsorption on Spherisorb ODS2 [33] in comparison to ethanol and n-propanol. For acetonitrile-water systems, the composite adsorption isotherm on C18 silica is reported in [20].…”

Section: Figurementioning

confidence: 99%

“…Chromatography, is firmly established as an essential technique for physicochemical investigations [9][10][11][12][13][14], however, research by the liquid chromatographic method on adsorption of binary mobile phases solutions, has not considered the most used in the HPLC practice stationary phases: hydrophobic and hydrophilic silicagel. HPLC can be successfully applied to determine adsorption isotherms [6,7,9,12,[15][16][17], by different procedures [18] which lead to practically identical results [19,20] and it has been demonstrated that in the case of adsorbents used in HPLC, the derived adsorption data are in good agreement [8,9,18,21] with those obtained by using the static methods [2,22] for adsorption studies. A common feature of the HPLC procedures is speed.…”

Section: Introductionmentioning

confidence: 99%

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HPLC study of the adsorption from solutions on two silicagels

1997

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SummaryIn this paper, we report and discuss the adsorption isotherms of hydro-organic mixtures and of compounds used as mobile phase in reversed phase and normal phase high performance liquid chromatography (RP-HPLC and NP-HPLC, respectively). This work is the first attempt to study the solid-liquid interface between two types of chromatographic silica surfaces and pure organic adsorbates from water and from organic eluents by HPLC. Frequently, among the dynamic techniques the method of choice for the measurement of an adsorption isotherm is frontal analysis. We suggest here the combination of the technique based on peak asymmetry calibration and peak profiles, which allows calculations directly from integration data. The group of systems studied permits the analysis of the intermolecular interactions on the silica surface. Particular attention was given to the system methanol-water and the measurement of the adsorption of n-octanol from methanol on RP-silica was also carried out.

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“…In order to understand the distribution of the solvent between the adsorbed phase and a bulk binary solution the excess adsorption of the organic modifier has to be described [21][22][23]. Solvent adsorption has been measured by many authors using the minor disturbance method [14,[24][25][26]. The excess amount of the adsorbed solvent changes with the surface properties of the stationary phase: the coverage density [16,21,27], the number of carbon atoms in the organic ligand [12,28,29] and the type of bonded ligand [30,31].…”

Section: Introductionmentioning

confidence: 99%